1. Field of the Invention
The present invention relates to telecommunication systems and, more particularly, to an apparatus and a method for ringing a subscriber""s wired and wireless mobile stations concurrently based upon a call to that particular subscriber""s published number.
2. Description of the Related Art
With the increasing popularity of wireless telecommunication systems (i.e, wireless cellular telephone systems), telecommunication service providers offer many different types of telecommunication services to their respective customers. Such services are generally provided to users on a subscription basis and, therefore, these users are generally referred to as xe2x80x9csubscribers.xe2x80x9d
Quite often, subscribers may have multiple telephones or stations at which they may be reached, such as a wired station at home or in the office and a wireless station. Accordingly, one category of telecommunication services offered to subscribers having multiple stationsxe2x80x94a wired station (i.e., a wired telephone) served by a wired telecommunications network and a wireless station (i.e., a mobile station) served by a wireless telecommunications networkxe2x80x94is to sequentially ring the wired and wireless stations upon the placement of a call to that particular subscriber""s published number.
A known method for providing such a call delivery service is to ring the subscriber""s wired and wireless stations sequentially. As illustrated in FIG. 1 for instance, when a call is placed to a subscriber""s published number, the call is routed to an end office or private branch exchange (PBX) 140 within the wired telecommunications network. The end office or PBX 140 causes the subscriber""s wired station 150 to initially ring and, if there is no answer on the wired station 150, the call is forwarded from the end office or PBX 140 in the wired telecommunications network to the wireless telecommunications network 130 to thereafter ring the subscriber""s wireless station 170.
Unfortunately, when the call is not initially answered by the subscriber at the wired station 150 according to this known method of call delivery, the calling party initiating the call to the subscriber may experience a delay between the ringing of the wired station and that of the wireless station. Additionally, as a result of forwarding the call to ring wireless station 170 in a different network 130, the calling party may also experience a prolonged ring time. As a result of such prolonged ring time, callers may have a tendency to abandon the call when the call at the first rung station 150 goes unanswered and before the call is transferred to and/or rings at the second station 170.
Accordingly, a call delivery method that rings the subscriber""s wired and wireless stations 150, 170 concurrently is desirable. The term xe2x80x9cconcurrentlyxe2x80x9d is used herein to mean more or less at the same time, and is not limited to necessarily ringing the stations synchronously with identical periods and duty cycles (on-time and off-time).
As illustrated in FIG. 1, however, such concurrent ringing of the subscriber""s wired and wireless stations 150, 170 is problematic because there are two different networks involved with the wired and wireless stations (e.g., the wired telecommunication network and the wireless telecommunication network 130) and these networks do not presently coordinate the interaction necessary to ring stations on both networks concurrently. It has also been difficult to concurrently ring a subscriber""s wired and wireless stations because the call set-up time for a wireless station is generally longer than that for a wired station.
In accordance with the present invention, a system and method are provided for concurrently ringing a subscriber""s wired and mobile stations, where the wired station is served by a wired telecommunications network and the mobile station is served by a wireless telecommunications network.
In an advantageous embodiment of the present invention, the call is routed to a network interface point of control from either the wired or wireless networks and the network interface becomes the point of control for the call. The call is initially offered to the mobile station by the network interface, and before the mobile station is rung, the call is offered to the wired station so that the wired and mobile stations ring concurrently.